The present invention relates generally to food steamers and, more particularly, to steamers designed for steaming food products at atmospheric pressures.
Commonly used steamers utilize pressure controls to turn on/off the heating elements which produce steam. This arrangement results in excessive steam loss, and requires the use of a closed, pressurized system. The closed system can result in flavor transfer form one product to another when products are being steamed simultaneously. For this reason, open system steamers or atmospheric type steamers in which the steam cavity is open to the atmosphere by a vent are also used. One problem experienced in such atmospheric steamers is again excessive steam losses due to the tendency of steam to migrate immediately toward and out of the vent opening. Such steam migration out of the vent opening also results in undesired temperature differences at different points in the steam cavity, as well as undesired temperature fluctuations in the steam cavity. Such undesired temperature differences in various parts of the cavity can also make it difficult to achieve suitable control of steam generation based upon monitoring temperature within the steam cavity.
Accordingly, it would be desirable to provide an improved atmospheric steamer construction which reduces steam losses and provides a more uniform and consistent temperature in the steam cavity.
In one aspect of the present invention, an atmospheric steamer includes a steam chamber defined at least in part by a housing, and a water retaining area having at least one associated heating element for heating the water to generate steam. A vent opening is provided through the housing. A steam diverting baffle is positioned around the vent opening to define a passage which leads to the vent opening. The baffle defines a passage opening for permitting steam to migrate towards the vent opening along the passage, with the passage opening being positioned to force steam to turn before proceeding toward the vent opening. The passage includes at least one drainage outlet for permitting steam which condenses in the passage to pass back to the water retaining area for further heating. The incorporation of the baffle within the steam chamber reduces steam losses by causing steam to condense inside the steam chamber as it loses energy in turning downward toward the vent.
In another aspect of the invention, an atmospheric steamer includes a steam chamber defined at least in part by a housing, and a water retaining area including at least one associated heating element for heating the water to generate steam which is provided to the steam chamber. A vent opening is provided through the housing. The vent opening leads to a vent path for venting gases from the steam chamber and a sensor is positioned along the vent path for sensing the passage of steam along the vent path. A controller receives an output from the sensor and controls the heating element. The controller is operable during a steaming operation to effect water heating responsively to the output received from the sensor.
In a preferred arrangement, the sensor may be a temperature sensor positioned along the vent path. The controller receives an output from the temperature sensor and controls the heating element such that heating of the water is stopped when a temperature in the vent tube reaches a threshold temperature indicative of steam exiting through the vent tube, and heating of the water is again initiated when the temperature in the vent tube falls below the threshold temperature by a predetermined amount.